Dialysis Chains and Access to Cadaveric Renal Transplantation Therapy Abstract Background. Previous research findings and public policy have focused extensively on the factors related to allocation of cadaveric donor kidneys in the U.S. among dialysis patients suffering from End Stage Renal Disease (ESRD). Kidney transplantation rates differ by sociodemographic characteristics, yet the reasons for this variation are not fully understood. Little is known about why such disparities exist and whether the interplay between dialysis facility chain status and patient case-mix, especially race, can further explain the variation in access to renal transplant therapy (RTT). Using Medicare program data and matching to Organ Procurement and Transplantation Network (OPTN) Kidney Wait List files, we will apply multilevel regression models to answer the following two research questions: Research Questions. We propose two research questions: Is there an independent (direct) effect of facility chain status on access to RTT? The hypothesis to be tested: Chain status is independently associated with patient access to RTT, after controlling for facility characteristics and patient case-mix. Can the lower RTT rates for Blacks, Hispanics, women and elderly be further explained by differences in a dialysis facility's chain status? The hypothesis to be tested: Chain status is another important explanatory factor accounting for the previously documented disparities in access to RTT by patient age, sex, race, and ethnicity. Study Design. This analysis will use a retrospective cohort design of incident hemodialysis patients and their providers with two main phases: 1) a 3-month baseline period following enrollment in the Medicare ESRD program, during which time all patient baseline characteristics will be obtained; and 2) a 7-year follow-up period that tracks the participants on the RTT wait- list, RTT procedures, death and censoring events. The study has two analyses, each with a different outcome measure. Analysis I: placement on the OPTN cadaveric kidney transplant waiting list during the 7-year follow-up period. Data on date of wait-listing will be obtained from the USRDS UNOS file; and Analysis II: time to 1st cadaveric transplantation since wait-listed, measured as the total number of days that a patient was active on the wait list Significance. Despite repeated attempts to reduce existing disparities in RTT, there have been limited improvements in this area, suggesting that our current understanding of the underlying mechanisms is limited and incomplete. We propose to examine an innovative new factor - the role of chain status - in access to RTT. Furthermore, given the vitriolic and ongoing debate on ways to improve access and equity in this treatment area, particularly in terms of racial differences, the role that the chains might play appears crucial and has to date not been examined. Achieving study objectives will provide important insights on the relationship between type of facility and RTT, aid clinicians and policy makers in achieving a more equitable access to RTT, and eventually improve care and outcomes of ESRD patients in the U.S. Finally, this study is consistent with Healthy People 2010 Objectives: Chronic Kidney Disease goals of decreasing racial and gender disparities in kidney transplantation rates.